The automated use of precision machining techniques is based upon precise movement of a motorized spindle through three-dimension space with a cutter chucked in the spindle. The cutter removes material based on its geometric relation to the spindle. A cutter with a known diameter is moved in precise, calculated strokes across the surface of the material being machined in order to produce a part. The cutter removes material based on its geometric relation to the spindle.
A cutter is a tool that has a radius which represents the offset between the axis of the cutter and the cutter's cutting edge. The cutter also has a length that indicates the distance between one end of the cutting edge and the other. The cutter sits within a chuck on the turning spindle and when spinning, the length and radius of the cutter determine the location and the amount of material that the cutter will remove.
To date, there have existed many commercial off-the-shelf computer products that derive a series of movements of the spindle in space based upon a cutter's dimensions (i.e. its radius and length) and a numeric model of the part to be produced. Because these products require a great deal of computational time and processing power, a traditional means of optimizing production has been through use of cutters with standardized dimensions. Using cutters with standardized dimensions, allows a manufacturer to use a single derivation in order to produce a given part. Manufacturers then purchase cutters of standardized dimensions and use them until such time as wear on the cutting edge make them ineffective for producing parts. The manufacturer then disposes of the cutter.
Cutters can be readily and effectively sharpened, but doing so shortens the radius of the sharpened cutter in comparison to its radius when new. When used in place of a standardized cutter, the sharpened cutter produces a part that is outside of tolerances. Rather than to produce parts that are out of tolerance, the cutters were not generally resharpened for use though nothing inherently prevented resharpening of the cutters.
In recent years, advances in the fabrication of silicon chips have resulted in much faster computers. Tasks that previously took hours or indeed days can be performed in minutes. The new speed and capability available on inexpensive computers has drastically cut the time necessary to derive the strokes necessary to produce a given part with a cutter of given dimensions.
There exists, therefore, an unmet need in the art to re-derive numeric control programs for the production of parts using previously sharpened cutters.